Axial decorrelation of paraxial wavefields: theory and experiment. - In: Fringe 2013, (2014), S. 213-216
Iterative phase retrieval and the important role played by initial conditions. - In: Fringe 2013, (2014), S. 123-128
Three-dimensional laser ablation for functionalization of non-planar optical surfaces. - In: Journal of laser applications, ISSN 1938-1387, (2013), 1, S. 919-925
Paper #N503
Efficient laser beam shaping is one of the keys to achieve maximum process performance and to exploit new application fields for lasers. However, with increasingly more complex beam shaping tasks typically the challenges related to system size, weight and reliability scale up as more and more conventional optical components like spherical lenses, gratings, prisms etc. are involved. To overcome this traditional tradeoff several optical functions can be integrated in a single hybrid [1] [2] (reflective/diffractive, refractive/ diffractive [3]) optical freeform component enabling miniaturized [4] and robust beam shaping solutions. For the fabrication of these complex optical surfaces we use integrated fabrication techniques (section 2), which combine micromachining of continuous reflective freeform surfaces [5] and precise laser ablation of high frequency diffractive structures efficiently [6]. In this article we focus on the generation of high quality diffractive structures in copper using 3-dimensional picosecond laser ablation within a five-axis ultraprecision micromachining center (section 3).
https://doi.org/10.2351/1.5062990
Parallelized chromatic confocal sensor systems. - In: Optical measurement systems for industrial inspection VIII, 2013, S. 87880V, insges. 10 S.
Freeform surfaces in optical microsystems: from parabasal theory to applications. - In: Freeform optics, ISBN 978-1-55752-986-2, (2013), insges. 3 S.
http://dx.doi.org/10.1364/FREEFORM.2013.FM2B.4
Dressing and selfsharpening of conventional tools. - In: Proceedings of the 13th International Conference of the European Society for Precision Engineering and Nanotechnology, (2013), S. 289-293
A theoretical comparison of Fresnel based digital holography and phase retrieval from the transport of intensity equation. - In: Tribute to H. John Caulfield, ISBN 978-0-8194-9683-6, 2013, 88330G, insges. 10 S.
Laser beam shaping - from source to application. - In: Congress proceedings, ISBN 978-0-912035-98-7, 2013, Short course 3, insges. 1 S.
Control over the spatial distribution of a wavefield, i.e. beam shaping, is increasingly important in a large variety of laser based applications ranging from illumination to material processing. After introducing the fundamentals of beam shaping, in this short course we discuss the specific benefits and drawbacks of the different beam shaping techniques with respect to the input beam parameters, the desired output field and the application. Besides standard solutions modifications of these approaches mainly aiming at spatial or temporal averaging for homogenization purposes are presented. All theoretical considerations are supported by practical examples and experimental results. In an overview typical technologies for realizing beam shaping components are summarized.
Low-cost uncooled infrared detector using thermo-mechanical micro-mirror array with optical readout. - In: AMA conferences 2013 proceedings, ISBN 978-3-9813484-3-9, (2013), S. 85-88
Planar integrated opto-fluidic microsystems in PMMA for particle analysis :
Planar-integrierte opto-fluidische Mikrosysteme aus PMMA für die Partikelanalyse. - In: Von Bauelementen zu Systemen, (2013), S. 149-152
We demonstrate an integrated optofluidic system for monitoring the particle mass concentration and the Sauter mean diamter of polydisperse floating suspensions of water and standardized test dust. For optimum integration, a planar emitter-receiver unit is developed and fabricated in silicon technology. A VCSEL at 850 nm serves as light source, and monolithically integrated segmented photodiodes detect both the attenuation of the primary light beam and the scattered light. The optical system is integrated into a planar transparent polymethyl-methacrylate substrate by micromilling of an optical freeform surface and electron beam evaporation of reflective layers following the concept of planar integrated free-space optical systems. We are able to detect 1 mg per liter of the standards ISO 12103-A3, -A3 and -A4 that contain particles with diameters from 0.5 to 150 [my]m and to determine the Sauter mean diameter of the particle size distribution.